Flight Dynamics Modeling of a Body Freedom Flutter Vehicle for Multidisciplinary Analyses

Kurzfassung

Integrated flight dynamic models play an essential role in all aircraft design phases. Examples are flight loads analysis for sizing of the structure, design of control laws, as well as design and analysis of missions. For these purposes, DLR has developed a robust, quick and unified process for generating, pre-processing and automatically integrating aircraft models. The process is called DLR Aircraft Model Integration Process (DAMIP) and is able to draw from a variety of different (best available) data sources. The DAMIP proce- dure is based on an unified environment, allowing aircraft modeling projects to be set-up in an easy and comfortable fashion. After this, the individual steps can be performed automatically, making it very suitable for the use in multidisciplinary design analysis and optimization loops. This paper outlines and demonstrates the DAMIP process as applied to the Body Freedom Flutter (BFF) vehicle that is currently studied and in-use at the De- partment of Aerospace Engineering at the University of Minnesota. In order to validate the integrated models the modal basis of the BFF vehicle is corrected by data obtained from ground vibration test (GVT). Linear state-space models are then generated to feed linear parameter-varying (LPV) system approaches and perform a flutter analysis by inspecting stability of the system matrices. The results are compared to those of the P-K Method analysis performed by Lockheed Martin Aeronautics. To demonstrate the flexibility of DAMIP, nonlinear models were generated in the equation-based, object-oriented Model- ica language and exported as S-functions to be used in the Matlab/Simulink simulation environment.